• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1410-1415
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• 2000

This paper introduces the experimental analysis of the resonator in the rolling piston type compressor for air conditioner. The resonator located between cylinder and bearing is a major factor in the noise reduction of the rotary compressor. Several shapes for the resonator which can be built in the space limitations are derived. Then optimal resonator type for the noise reduction is determined by noise tests. 6 design parameters of the type are found and optimal level for each design factor is deduced from Taguchi method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.1-8
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• 1996

This paper proposes a novel transversal filter and an optimal LMS algorithm, and show how these can be realized as an adaptive equalizer. The transversal filter consists of a walsh and block pulse functions. in the LMS algorithm with equalizers, the convergence factor is an improtant design parameter because it governs stability and convergence speed. The conventional adaptation techniques use a fixed time constant convergence factor by the trial and error method. In this paper, an optimal method in the choice of the convergence factor is proposed. The proposed algorithm is obtrained that is tailored for each filter tap and is updated at each iteration. The performance of the proposed algorithm is compared iwth those of the conventional TDL and DFT equalizers by computer simulations.

• Journal of Aerospace System Engineering
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• v.9 no.4
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• pp.55-61
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• 2015

In this study, we peformed optimal design of a composite skid landing gear, one of the solid spring shock absorbers, for light vertical takeoff and landing aircraft. Although a solid spring type has poor energy dissipation capability, it is commonly used for light aircraft where sink speeds are low and shock absorption is non-critical in terms of simplicity, low cost and weight reduction. In this paper, design parameters of solid spring such as sink speed, gear leg length, deflection and landing load factor were reviewed. In order to meet structural requirements such as deflection and strength, finally, we conducted optimal design of the composite skid landing gear for VTOL UAV using genetic algorithm and pattern search algorithm.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.357-363
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• 2022

In this study, in order to develop an non-slip metal grating, the stability of the grating according to the span of the grating and the gap and height of the bearing bar was evaluated. The optimal shape design of the grating was performed using the results of determining the stability of the grating. The purpose of this study is to determine the stability according to the spacing and height of the bearing bar by applying the design pressure at the design stage to develop the anti-skid grating, and to design the optimal shape for cost reduction. In the optimal design, the target variable was set as the mass, and the optimal design of the grating was performed based on about 20%. Regardless of the height of the bearing bar of the grating, the stress and deformation of the span and the grating showed a proportional tendency to each other, and it was found that the stress decreased as the height of the bearing bar increased. Based on the structural analysis results, an optimal design was performed using mass as the objective variable, and the existing 2mm thickness was changed to 1.6mm, reducing the mass by about 19%. The stress increased by about 4.4% compared to the maximum stress of the existing grating, but the minimum safety factor was 3.1, indicating that the optimally designed grating was stable.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.645-648
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• 1998

We used a three-dimensional inductance extraction program, Fasthenry for optimal design of the spiral inductors on silicon substrate. The inductance and quality factor of the spiral inductors with various design parameters were calculated so that the optimal parameter value was determined. The spiral inductors then were fabricated using different foundary processes and were measured using the network analyzer and microwave probes. The pad and other parasitics of measurement system were de-embedded using the y-parameter calibration technique. the inductors fabricated using the LG 0.8um process and HP 0.5um process showed the quality factor of 5.8 and 3, respectively. Finally the equivalent circuit farameters of the spiral inductors on silicon substrate were extracted from the measurement data using the matlab.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.278-291
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• 1994

A computer-aided robust design (CARD) technique is developed to search for the design variables, optimal as well as robust in the sense of Taguchi method. The CARD technique can effectively handle inequality problems by employing the variable penalty method, and dynamic problems with many design variables and/or with mixed discrete and continuous variables. It is also capable of providing contributions of each design variables to the object funtion and information for future designs. As the illustrative examples, two dynamic systems, engine mounting system and in-line feeder, are treated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.6
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• pp.619-624
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• 2015

Owing to miniaturization and low-power electronics, mobile, implanted, and wearable devices have become the main trends of electronics during the past decade. There has been much research regarding energy harvesting to achieve battery-free or self-powered devices. The optimal design problems of a double-pendulum kinetic-energy harvester from human motion are studied in this paper. For the given form factor, the weight of the harvester, and the known human excitation, the optimal design problem is solved using a dynamic non-linear double-pendulum model and an electric generator. The average electrical power was selected as the performance index for the given time period. A double-pendulum harvester was proven to be more efficient than a single-pendulum harvester when the appropriate parameters were used.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.882-886
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• 2004

A nation have the regulation for a vehicle safety and interested in the side impact of a vehicle. But we spend a lot of money and time for the side impact test. So we must design a vehicle parts regard to the side impact test. This paper describes a new test method for side impact test. We used DFSS(Design For Six Sigma) process for design of door trim armrest. We searched the door trim armrest control factor and made the experiment plan. We researched the optimal design factor and improved the abdomen injury value of the human dummy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.4
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• pp.61-67
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• 1985

This study is concerned with the optimum design of reinforced concrete frame structure with multi-stories and multi-bays by Limit State Design Method aimed to establish a synthetical optimal method that can simultaneously acomplish structural analysis and sectional desig. For optimum solution, the Successive Linear Programming known as effective to nonlinear optimization problem: including both multi-design variables and mulit-constrained condition was applied. The developed algorithm was applied to an actual structure and reached following results. 1)The developed algorithm was rvey effective converging to an optimal solution with 3 to 5 iteration. 2)An optimal solution was showed when bending moment redistribution factor a was 0.80. 3)The column was, regardless of story, controlled by the long column when unbraced, while in case of braced column, it is designed with 3 short column controlled by thrust and bending moment, and the supporting condition had little effect on the optimization results.

• Transactions of Materials Processing
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• v.24 no.5
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• pp.332-339
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• 2015

In the current paper, a cold forging sequence was developed to manufacture a precisely cold forged H/Lower, which is used as the air back unit in commercial automobiles. The preform shape of the H/Lower influences the dimensional accuracy and stiffness of the final product. The shape factor (SF) ratio and shape of the tools are considered as the design parameters to achieve adequate backward extrusion height and maintain appropriate thickness variations. The optimal conditions of the design parameters were determined by using an artificial neural network (ANN). To experimentally verify the optimal preform and tool shapes, the experiments of the backward extrusion of the H/Lower were executed. The process design methodology proposed in the current paper, can provide a more systematic and economically feasible means for designing the preform and tool shapes for cold forging.